Pain in the Neck

Use tennis balls to explore inertia and how to prevent whiplash injuries in rear-end crashes.

Key Questions

• What is whiplash?
• How does Newton's first law of motion affect the type and severity of head/neck injuries resulting from rear-end collisions?
• How do well-designed vehicle head restraints help prevent head/neck injuries in a rear-end collision?

Student Directions

1. View the Introduction video.
2. Download and print the Student Activity Sheets.
3. Start the activity and answer the Analysis Questions as you work through the Procedure.
4. For Step 7 in the Procedure, watch the video "Inside IIHS: Rear testing for whiplash prevention" located in the Video Gallery (see above) and complete the fill-in-the-blank statements on your activity sheet.
5. View the Conclusion video located in the Video Gallery (see above) and finish answering the Analysis Questions.
6. (Optional) View the "It's Basic Physics" Inertia video segment and/or the "Apple on Rod" inertia demo video in the Video Gallery (see above) to review the concept of inertia.

Head restraint: a vehicle seat safety device designed to limit the backward movement of an adult occupant's head in a rear-end collision in order to reduce the risk of neck injury.

Newton's First Law of Motion: an object at rest will remain at rest and an object in motion will remain in motion unless acted on by an outside force.

Whiplash: a variety of sprains, strains and other neck injuries caused by a severe jerk to the head that can occur in rear-end vehicle collisions.